The windows in the shop building are old, metal frame, single-pane glass and barely slide, but I was willing to live with them, as replacing exterior windows in load-bearing walls is expensive and time-consuming.  Then an opportunity came along that I couldn't resist.

I volunteer every other weekend at the Habitat for Humanity ReStore, taking in donations, cleaning them up, pricing them and stocking the shelves. After my shift one Saturday, I went to a home show down in San Luis Obispo, still wearing my ReStore t-shirt.  As I wandered around the booths I noticed quite a few window vendors so I asked a few about cheap, low-end, double-pane vinyl windows.  The prices were still a little high until I spoke with one company in Morro Bay. The owner said he had two windows that were so big that nobody would buy them - one was 8' x 5' and the other was 8' x 4'. Both have a central fixed pane and a sliding pane on the right and left.  He said he would donate them to the Habitat ReStore if someone would come and pick them up. So the next day I drove down and picked up the windows and brought them back to my workshop.  The next time I went to work at the ReStore, I told the story to the manager and bought the windows at the normal ReStore rate. So the window vendor got rid of his unsellable windows, ReStore got a substantial donation from me, and I got two huge, energy efficient windows for a small fraction of what they would have cost new.  Good deal all around!

Now the hard work came.  I had to rip off the drywall around each window, pull out the old windows, frame in the new opening (including 4"x8"x8' headers), install the new windows and re-do the trim.  Here's how that went with the south-facing window:

And similarly with the west-facing window: